Frequency-specific efficacy of intratympanic steroid on idiopathic sudden sensorineural hearing loss.

Background: Hearing recovery would be different in each sound frequency in patients with idiopathic sudden sensorineural hearing loss (ISSNHL).Aims/objectives: To analyze frequency-specific efficacy of intratympanic steroid on ISSNHL.Materials and methods: Of a total of 381 patients with ISSNHL (hearing threshold ≥40 dB; ≤30 days until treatment), 174 patients (174 ears) received systemic steroid plus hyperbaric oxygen therapy (HBO group), and 207 patients (208 ears) received systemic plus intratympanic steroid (IT group). Hearing thresholds at 125-8000 Hz were measured at every octave before and after treatment.Results: % of patients with hearing gains ≥10 dB in the IT group was significantly higher for 500 Hz and the average of 5 mid-frequencies, tended to be higher for 1000 Hz, but was significantly lower for 8000 Hz, compared to the HBO group. Multiple regression analysis showed that hearing recovery was negatively correlated with patients' age for 125/2000/4000/8000 Hz and with days from onset to treatment for all frequencies, and also revealed better hearing recovery at 500/1000 Hz in the IT group than in the HBO group.Conclusions: Intratympanic steroid is more effective than hyperbaric oxygen to yield better hearing outcomes at mid-frequencies and would be advantageous to restore sound/speech perception.Significance: Superiority of intratympanic steroid over hyperbaric oxygen for treating ISSNHL was verified.

Expression of Cl- channels/transporters in nasal polyps.

PURPOSE: Nasal polyp formation is a common sequela of prolonged chronic rhinosinusitis, but the mechanism underlying this disease state is still controversial. We compared the expressions of Cl- channels/transporters in nasal polyps with those in inferior turbinates to explore whether a deficiency in Cl- transport may participate in the pathophysiology of nasal polyp formation as in patients with cystic fibrosis. METHODS: Nasal polyps and inferior turbinates were collected from 12 chronic rhinosinusitis patients with hypertrophic rhinitis and/or nasal polyps. Expressions of cystic fibrosis transmembrane conductance regulator (CFTR), pendrin, Na+-K+-2Cl- cotransporter 1 (NKCC1), SLC26A3, TMEM16A and anion exchanger 2 (AE2) were examined by fluorescence immunohistochemistry using Alexa Fluor 488. RESULTS: CFTR was weakly expressed on the epithelial surface of the turbinate mucosa whereas the nasal polyps showed almost no fluorescence. Pendrin was mainly expressed on the epithelial surface in both tissues. The fluorescence was moderate in the nasal polyps and strong in the turbinate mucosa. For NKCC1, moderate fluorescence was observed throughout the entire epithelial layer of the nasal polyps, but the turbinate mucosa exhibited almost no fluorescence. On the other hand, no fluorescence for SLC26A3, TMEM16A or AE2 was seen in either tissue. CONCLUSION: These results suggest that CFTR, pendrin and NKCC1 may participate in the pathogenesis of nasal mucosal edema and play roles in the mechanism of nasal polyp formation.

Calmodulin and protein kinases A/G mediate ciliary beat response in the human nasal epithelium.

BACKGROUND: Mucociliary clearance of the airway epithelium is an essential function for mucosal defense. We recently proposed a hypothetical mechanism of ciliary beat regulation, in which the pannexin-1 (Panx1)-P2X7 unit serves as an oscillator generating a periodic increase in intracellular Ca2+ ([Ca2+ ]i ). In the present study, we examined the localization of Panx1 and P2X7 at the ultrastructural level, and investigated the regulatory pathway subsequent to [Ca2+ ]i increase. METHODS: The inferior turbinate mucosa was collected from patients with chronic hypertrophic rhinitis during endoscopic sinonasal surgery. The mucosa was examined by transmission immunoelectron microscopy for Panx1 and P2X7. Alternatively, the mucosa was cut into thin strips, and ciliary beat frequency (CBF) was measured under a phase-contrast light microscope with a high-speed digital video camera. RESULTS: In immunoelectron microscopy, immunoreactivities for Panx1 and P2X7 were localized along the plasma membrane of the entire length of the cilia. CBF was significantly increased by stimulation with 100 µM acetylcholine (Ach). The Ach-induced CBF increase was significantly inhibited by calmidazolium (calmodulin antagonist), SQ22536 (adenylate cyclase inhibitor), ODQ (guanylate cyclase inhibitor), KT5720 (protein kinase A inhibitor), and KT5823 (protein kinase G inhibitor). Fluorodinitrobenzene (creatine kinase inhibitor) completely inhibited the ciliary beat in a time- and dose-dependent manner. CONCLUSION: These results indicate that Panx1 and P2X7 coexist at the cilia of the human nasal epithelial cells and that the ciliary beat is regulated by calmodulin, adenylate/guanylate cyclases and protein kinases A/G, and crucially depends on creatine kinase.

Efficacy of Intratympanic Steroid on Idiopathic Sudden Sensorineural Hearing Loss: An Analysis of Cases With Negative Prognostic Factors.

Purpose We retrospectively studied the efficacy of intratympanic steroid administration in comparison with hyperbaric oxygen (HBO) therapy for idiopathic sudden sensorineural hearing loss (ISSNHL) with negative prognostic factors. Method We enrolled 301 patients (302 ears) with ISSNHL (average hearing level at 250-4000 Hz ≥ 40 dB; time from onset to treatment ≤ 30 days). From August 2002 to March 2009, 174 patients (174 ears) received systemic steroid plus HBO therapy (HBO group), and from June 2015 to January 2018, 127 patients (128 ears) received systemic plus intratympanic steroid (IT group). Hearing outcomes were evaluated by 6 indices: cure rate, marked-recovery rate (percent of patients with hearing gain ≥ 30 dB), recovery rate (percent of patients with hearing gain ≥ 10 dB), hearing gain, hearing level after treatment, and percent hearing improvement compared to the unaffected contralateral ear. Results The recovery rate was significantly higher in the IT group than in the HBO group (80.5% vs. 68.4%, p = .019). The IT group showed a higher recovery rate than the HBO group in patients aged ≥ 60 years ( p = .010), patients with early (≤ 7 days from onset) treatment ( p = .005), patients with initial hearing levels ≥ 90 dB ( p = .037), and patients with vertigo/dizziness ( p = .040). The IT group also showed higher hearing gain and percent hearing improvement than the HBO group in patients with vertigo/dizziness ( p = .046 and p = .026, respectively). Conclusions Systemic plus intratympanic steroid is more effective for ISSNHL than systemic steroid plus HBO, particularly in patients with negative prognostic factors, such as old age, profound hearing loss, and/or presence of vertigo/dizziness.

Comparison of 2 and 4 Intratympanic Steroid Injections in the Treatment of Idiopathic Sudden Sensorineural Hearing Loss.

OBJECTIVE: We studied the effect of intratympanic steroid administration with different total injection times on hearing outcomes in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). METHODS: The subjects were 191 consecutive patients (192 ears) with ISSNHL (hearing level ≥40 dB, interval between onset and treatment ≤30 days). They received systemic prednisolone (100 mg followed by tapered doses) combined with intratympanic injection of dexamethasone (4 mg/ml). Intratympanic injection was performed 4 times (days 1, 2, 4, and 7) in 92 patients (92 ears) or 2 times (days 1 and 2) in 99 patients (100 ears). The hearing outcomes were evaluated at 1 week from the start of treatment and 1 to 2 months after the completion of treatment. RESULTS: There was no significant difference in hearing outcomes between the 4- and 2-injection groups at either time point. Multiple regression analysis also showed that the hearing level after treatment did not depend on the total number of intratympanic steroid injections. CONCLUSION: These results indicate that a protocol using only 2 intratympanic steroid injections exerts a sufficient effect on the hearing outcomes of ISSNHL. This simplified treatment protocol would be greatly beneficial to relieve the physical and mental stress of patients.

Expressions of TRPVs in the cholesteatoma epithelium.

OBJECTIVE: We have recently proposed a hypothesis that acid leakage through the cholesteatoma epithelium mediates bone resorption in middle ear cholesteatoma. In the present study, we investigated the expressions of transient receptor potential vanilloid (TRPV) channels, which have been shown to play roles in the regulation of epidermal barrier function, in the cholesteatoma epithelium in comparison with the normal skin. METHODS: Cholesteatoma epithelium and postauricular skin were collected from 17 patients with primary acquired middle ear cholesteatoma who underwent tympanomastoidectomy. Expressions of TRPV1, TRPV3, TRPV4, and TRPV6 were explored by fluorescence immunohistochemistry and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). RESULTS: TRPV1, TRPV3, TRPV4, and TRPV6 mRNAs were all detected by qRT-PCR both in the skin and cholesteatoma tissue. Immunohistochemical staining showed that TRPV1 and TRPV3 were positive in the viable cell layers of the epidermis of the skin, and only TRPV3 was positive in those of the cholesteatoma epithelium. The immunoreactivity for TRPV3 was significantly weaker in cholesteatoma than in the skin. CONCLUSIONS: The lower expression of TRPV3 in cholesteatoma may be one of the mechanisms underlying the increased permeability of this tissue. On the other hand, TRPV1, TRPV4, and TRPV6 are unlikely to be involved in the regulation of epithelial permeability in cholesteatoma.

Possible contribution of pannexin-1 to capsaicin-induced ATP release in rat nasal columnar epithelial cells.

Current evidence indicates that transient receptor potential (TRP) channel activity involves a relationship between opening of pannexin-1 and release of ATP into the extracellular space. We examined the effects of agonists of thermosensitive TRP channels (TRPM8, TRPA1, TRPV1, and TRPV2) on ATP release from rat nasal mucosa, and measured ciliary beat frequency (CBF) using digital high-speed video imaging. Single-cell patch clamping from dissociated rat nasal columnar epithelial cells was performed to confirm the relationship between pannexin-1 and TRP. We demonstrated that ATP release and CBF were significantly potentiated by the heat-sensitive TRPV1 agonist capsaicin (10 µM), but not by other TRP agonists. Capsaicin-induced ATP release and CBF increase were significantly inhibited by the pannexin-1 blockers carbenoxolone (10 µM) and probenecid (300 µM). In addition, the voltage step-evoked currents in the presence of capsaicin were inhibited by the pannexin-1 blockers in single-cell patch clamping. Our results suggest the participation of TRPV1 and pannexin-1 in the physiologic functions of rat nasal mucosa.

Acetylcholine-induced ex vivo ATP release from the human nasal mucosa.

OBJECTIVE: The present study aimed at investigating ATP release in response to acetylcholine (Ach) and pharmacologically elucidating the intracellular signal transduction pathway of this reaction in an ex vivo experiment. METHODS: The inferior turbinate mucosa was collected from 21 patients with chronic hypertrophic rhinitis who underwent endoscopic turbinectomy. The mucosa was shaped into a filmy round piece, and incubated with chemical(s) in Hank's balanced salt solution for 10min. After incubation, the ATP concentration was measured by a luciferin-luciferase assay. RESULTS: The baseline release of ATP without stimulus was 57.2±10.3fM. The ATP release was significantly increased by stimulation with 100µM Ach. The Ach-induced ATP release was completely inhibited by removing extracellular Ca2+. Significant inhibition of the Ach-induced ATP release was also observed by the addition of 1µM atropine, 40µM 2-APB, 10µM CBX, and 100µM PPADS, whereas 30nM bafilomycin A1 did not affect the ATP release. CONCLUSION: These results indicate that the Ach-induced ATP release from the human nasal mucosa is dependent on the pannexin-1 channel and purinergic P2X7 receptor, suggesting that these two molecules constitute a local autocrine/paracrine signaling system in the human nasal epithelium.